To comprehensively evaluate a European-American child with severe hypertension, whole-exome sequencing (WES) was performed on the child and parents, which identified causal variation of the proband's early-onset disease. The proband's hypertension was resistant to treatment, requiring a multiple drug regimen including amiloride, spironolactone, and hydrochlorothiazide. We suspected a monogenic form of hypertension because of the persistent hypokalemia with low plasma levels of renin and aldosterone. To address this, we focused on rare functional variants and indels, and performed gene-based tests incorporating linkage scores and allele frequency and filtered on deleterious functional mutations...

Liddle syndrome is a rare autosomal dominant monogenic form of hypertension. The authors analyzed clinical and genetic features of 12 cases of Liddle syndrome, the largest sample size ever reported. Clinical data were studied retrospectively. The exon 13 of the β and γ subunits of the epithelial sodium channel were amplified and sequenced in the peripheral blood leukocytes of the patients. The onset age of the 12 patients was 15.5±3.3 years. Their blood pressures were poorly controlled, and serum potassium levels in most patients were <3...

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation...

Human primary or essential hypertension is a complex, polygenic trait with some 50% contribution from genes and environment. Richard Lifton and colleagues provided elegant dissection of several rare Mendelian forms of hypertension, exemplified by the glucocorticoid remediable aldosteronism and Liddle's syndrome. These discoveries illustrate that a single gene mutation can explain the entire pathogenesis of severe, early onset hypertension as well as dictating the best treatment. The dissection of the much more common polygenic hypertension has proven much more difficult...

Human primary or essential hypertension is a complex, polygenic trait with some 50% contribution from genes and environment. Richard Lifton and colleagues provided elegant dissection of several rare Mendelian forms of hypertension, exemplified by the glucocorticoid remediable aldosteronism and Liddle's syndrome. These discoveries illustrate that a single gene mutation can explain the entire pathogenesis of severe, early onset hypertension as well as dictating the best treatment.The dissection of the much more common polygenic hypertension has proven much more difficult...

Human primary or essential hypertension is a complex, polygenic trait with some 50% contribution from genes and environment. Richard Lifton and colleagues provided elegant dissection of several rare Mendelian forms of hypertension, exemplified by the glucocorticoid remediable aldosteronism and Liddle's syndrome. These discoveries illustrate that a single gene mutation can explain the entire pathogenesis of severe, early onset hypertension as well as dictating the best treatment. The dissection of the much more common polygenic hypertension has proven much more difficult...

Human primary or essential hypertension is a complex, polygenic trait with some 50% contribution from genes and environment. Richard Lifton and colleagues provided elegant dissection of several rare Mendelian forms of hypertension, exemplified by the glucocorticoid remediable aldosteronism and Liddle's syndrome. These discoveries illustrate that a single gene mutation can explain the entire pathogenesis of severe, early onset hypertension as well as dictating the best treatment.The dissection of the much more common polygenic hypertension has proven much more difficult...

INTRODUCTION: Definite paucity of data pertaining to spectrum of renal and urinary tract diseases in our state and in various parts of India forms the basis of this study. Available data has emphasized more on specific clinical syndromes and chronic renal diseases rather than over all spectrums of renal and urinary tract diseases, that too in adult population. AIM: The present study a retrospective analysis, forms one of the basic data of paediatric nephrology and urology related disorders in our state...

The ENaC/degenerin ion channel superfamily includes the amiloride-sensitive epithelial sodium channel (ENaC) and acid sensitive ionic channel (ASIC). ENaC is a multimeric ion channel formed by heteromultimeric membrane glycoproteins, which participate in a multitude of biological processes by mediating the transport of sodium (Na(+)) across epithelial tissues such as the kidney, lungs, bladder, and gut. Aberrant ENaC functions contribute to several human disease states including pseudohypoaldosteronism, Liddle syndrome, cystic fibrosis, and salt-sensitive hypertension...

Cushing's syndrome (CS) is defined as a constellation of clinical signs and symptoms occurring due to hypercortisolism. Cortisol excess may be endogenous or exogenous. The most common cause of CS is glucocorticoid therapy with supraphysiological (higher than in the case of substitution) doses used in various diseases (e.g. autoimmune). One possible CS cause is ectopic (extra-pituitary) ACTH secretion (EAS) by benign or malignant tumours. Since its first description in 1963, EAS aetiology has changed, i.e. as well as small cell lung cancer (SCLC), higher incidence in other malignancies has been reported...

CONTEXT: Androgen excess may be adrenal and/or ovarian in origin; we hypothesized that a subgroup of patients with polycystic ovarian syndrome (PCOS) may have some degree of abnormal adrenocortical function. OBJECTIVE: The objective of the study was to evaluate the pituitary adrenal axis with an oral low- and high-dose dexamethasone-suppression test (Liddle's test) in women with PCOS. DESIGN: This was a case-control study. SETTING: The study was conducted at the National Institutes of Health Clinical Center...

Liddle syndrome (LS) is a familial disease characterized by early onset hypertension (HT). Although regarded as rare, its incidence may be greater than expected because the classical findings of hypokalemic metabolic alkalosis with suppressed renin and aldosterone levels are not consistently present. Herein, we present the case of an adolescent boy and maternal relatives who were followed up with misdiagnosis of essential HT for a long duration. Clinical diagnosis of LS was confirmed on genetic analysis. Despite carrying the same mutation, the index patient and the family members manifested heterogeneous phenotypes of the disease including age at presentation, degree of HT, presence of hypokalemia and renal/cardiac complications...

Epithelial sodium channels (ENaCs) play critical roles in the maintenance of fluid and electrolyte homeostasis, and their genetic abnormalities cause one type of hereditary salt-sensitive hypertension, Liddle syndrome. As we reported previously, both human and rodent Nedd4L/Nedd4-2 showed molecular diversity, with and without a C2 domain in their N-terminal. Nedd4L/Nedd4-2 isoforms with a C2 domain are hypothesized to be related closely to ubiquitination of ENaCs. We generated Nedd4-2 C2 domain knockout mice...

Pseudohyperaldosteronism is characterized by a clinical picture of hyperaldosteronism with suppression of renin and aldosterone. It can be due to endogenous or exogenous substances that mimic the effector mechanisms of aldosterone, leading not only to alterations of electrolytes and hypertension, but also to an increased inflammatory reaction in several tissues. Enzymatic defects of adrenal steroidogenesis (deficiency of 17α-hydroxylase and 11β-hydroxylase), mutations of mineralocorticoid receptor (MR) and alterations of expression or saturation of 11-hydroxysteroid dehydrogenase type 2 (apparent mineralocorticoid excess syndrome, Cushing's syndrome, excessive intake of licorice, grapefruits or carbenoxolone) are the main causes of pseudohyperaldosteronism...

The epithelial sodium channel (ENaC) is rate limiting for Na(+) absorption in the aldosterone-sensitive distal nephron comprising the late distal convoluted tubule (DCT2), the connecting tubule (CNT), and the entire collecting duct. Liddle syndrome (pseudohyperaldosteronism), a severe form of salt-sensitive hypertension, is caused by gain-of-function mutations of ENaC, but the precise tubular site of increased ENaC function is unknown. In the cortical collecting duct (CCD), ENaC is known to be regulated by aldosterone...

The epithelial sodium channel (ENaC) is composed of three homologous subunits and allows the flow of Na(+) ions across high resistance epithelia, maintaining body salt and water homeostasis. ENaC dependent reabsorption of Na(+) in the kidney tubules regulates extracellular fluid (ECF) volume and blood pressure by modulating osmolarity. In multi-ciliated cells, ENaC is located in cilia and plays an essential role in the regulation of epithelial surface liquid volume necessary for cilial transport of mucus and gametes in the respiratory and reproductive tracts respectively...

These studies test whether three disease-causing mutations in genes (SCNN1A and SCNN1G) encoding subunits of the epithelial Na(+) channel, ENaC, affect the biophysical and gating properties of this important renal ion channel. The S562P missense mutation in αENaC and the K106_S108delinsN mutation in γENaC are associated with pseudohypoaldosteronism type 1 (PHA1). The N530S missense mutation in γENaC causes Liddle's syndrome. Incorporation of S562P into αENaC and K106_S108N into γENaC resulted in significant decreases in macroscopic ENaC currents...

Clinical genetics plays a central role in the diagnostic practice, mainly due to both the hereditary and non-hereditary genetic component, which characterizes most of the diseases. This branch of medicine has been characterized by a rapid technological growth since 2003, when the entire human genome was sequenced. We need to consider the reduction in terms of both time and costs that the gene sequencing has gone through. Before, 13 years and about three billion dollars were needed, now it takes only a few weeks and about ten thousand dollars to sequence the entire human genome...